Hydro: How micro is too micro?

InsolatedInsolated Registered Users Posts: 11 ✭✭
I'm buying land that includes a spring-fed pond, with water constantly flowing out of the overflow pipe. For context, I'm looking into going off-grid using primarily solar -- I know that's a big discussion in itself, but I'd like to leave that to a later post, if you would, please. I want to discuss micro-hydro first so that, if it's not worth it, I can put it out of my mind and have less to focus on. (The summary on why off-grid: Tax credits of 30% federal and 25% state make batteries more attractive compared to a $6,000 grid connection cost.)

The basic question: At what low wattage is installing micro-hydro not worth it? I don't know my loads yet, so I'm looking for guidelines and opinions; though I expect consumption of at least 10 kWh/day. I look at the hydro as offsetting lack of solar when it's raining or perhaps even just cloudy.

Before I get into details, thank you to everyone in this community for all the information you provide on a daily basis. I've read this forum for around a year now and have learned a lot.

* Pond size: 1 acre
* Head (overflow pipe outlet): 11 - 21 m lower than pond surface (imprecision due to using GPS)
Flow (sunny day, i.e. worst-case scenario): 0.625 L/s (determined using a bucket and timer, measured 3 times)

Using PowerSpout.com's calculator (50 m pipe length, 100 mm pipe diameter), that's only 0.576 - 1.200 kWh/day, before losses. At, say, $1,875 ($2,500 before 25% state credit) to add the micro-hydro to the off-grid solar, amortized over 10 years, the addition costs $0.89/kWh - $0.43/kWh (again, before losses).

How does rain improve that? I don't know. Annual rainfall is supposedly 44.59 inches in Columbia, SC. But how do I use that to estimate additional wattage from rain? That's apparently 4.5 million liters/year on a 1-acre pond, but isn't it too simplistic to just turn that into an additional 0.145 L/s?

Thank you for your time.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,637 admin
    edited October 2016 #2
    How much power/energy per day are you planning on using? 10 kWH per day is not that large for a US home (300 kWH per month). For off grid, it is possible to get down towards 3.3 kWH per day (near normal electric life, lots of conservation, propane/solar thermal for heating/hot water/cooking). Run lights, full size energy star refrigerator, clothes washer, well pump, tv, laptop computer, etc.

    One thing to watch for, private dams can be an issue (safety, regulation). As well as water rights (if dam "attracts attention").

    http://www.scdhec.gov/environment/WaterQuality/DamsReservoirs/

    http://www.thestate.com/news/local/article41315256.html

    Assuming the balance of system (battery bank, charge controllers, AC inverter, etc.) are all pretty much "fixed costs"--The amount of solar to provide 1.2 kWH per day:
    http://www.solarelectricityhandbook.com/solar-irradiance.html

    Columbia
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 56° angle from vertical:
    (For best year-round performance)
    Jan Feb Mar Apr May Jun
    3.67
     
    4.03
     
    4.89
     
    5.47
     
    5.40
     
    5.23
     
    Jul Aug Sep Oct Nov Dec
    5.18
     
    4.95
     
    4.81
     
    4.80
     
    4.05
     
    3.67
     

    Hydro is great for winter/when you have water... So comparing to worst case average winter sun of 3.67 hours per day:
    • 1,200 WH per day * 1/0.77 panel+controller deratings * 1/3.67 hours of sun (Dec-Jan average) = 425 Watt array
    You can get solar panels for ~$1 per watt in quantity (upwards of $2 per watt with shipping)... Cheaper than hydro... Probably less work to install and maintain.

    Can you find a turbine that small (efficient) at 1,200 WH / 24 hours per day = 50 Watt turbine rating....

    Your thoughts?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • InsolatedInsolated Registered Users Posts: 11 ✭✭
    Bill, thank you for replying. I will read through those links -- I'm impressed by your thoroughness. Let me first answer generally, then provide details at the end.

    I'm in the early stages of planning the house, and hope to make it as efficient as is reasonable. (I will have plenty of questions on that front, but am first seeing what the builder proposes as a starting point.) I expect the loads I can size currently will be dwarfed by those I can't yet (e.g. laptop vs. well pump). I also want to discuss at some point how to keep as much load as possible within the daylight hours, to keep the battery bank size reasonable.

    As you show, solar panels are cheaper; reframing my question, what's the minimum power from hydro one would consider worth the cost in scenarios where the solar isn't producing? If it rains more days straight than the days of autonomy the battery bank was sized for, but the hydro keeps the food in your fridge from spoiling, is that sufficient? Obviously, generators come into the discussion at this point.

    I plan to overpanel, so I'm thinking of two types of loads: Opportunistic (avoid using power from batteries) vs. needed-now (use batteries if necessary).

    "Defining" loads:
    1. Geothermal heat pump or alternative (needs discussion): A/C is mostly opportunistic (hotter when sun is shining); heat unfortunately isn't (that may lead into e.g. the solar thermal you mentioned). I'm hoping the pond will make the ground loop cheap enough for geothermal to be a reasonable cost. kWh/day: Not known yet.
    2. Electric car: It's a Volt, so I can use gas directly if needed; therefore, let's call it opportunistic. For simplicity, assume it requires 7 kWh/day (less than full charge).

    I'm sure we're already past 10 kWh/day at this point. What comes next? Well pump, fridge, microwave, etc.; but I'm unable to size those yet.

    Answering your questions directly:
    1. How much power/energy per day are you planning on using? At this early stage, my target would be 10 - 30 kWh/day. I hope to reduce that range as the planning continues, and place as much demand in sunlight hours as possible.
    2. Can you find a turbine that small ...? I was looking at the PowerSpout Pelton; the calculator used for the original post is supposed to be accurate for that turbine. I haven't seen a smaller one yet.

    Questions:
    1. I was hoping to paint in broad strokes first to have a better understanding, then work my way into getting each load accurately defined; do you feel I should simply wait until I can specify each individual load?
    2. I'm trying to carve out topics to discuss so I can focus on one piece at a time and avoid being overwhelmed (hence asking about hydro even though I plan on using primarily solar). Do I instead just need to post the full picture and wade through it with those willing to comment?
  • BB.BB. Super Moderators, Administrators Posts: 29,637 admin
    From an "engineering" point of view--10% of your power from hydro (i.e. 1.2 kWH per day vs 10-15 kWH per day load) is almost a don't care--It is round off error.

    1.2 kWH per day is enough to keep a full size energy star rated refrigerator going--So, it may be worth it from that point of view--But your day to day loads are 10x that amount. If you put in a Water Turbine (or a typical wind turbine), you do need a diversion controller and dump load--Turbines generally need a dump load (heater/resistor bank) to burn up excess power once the battery bank is fully charged (at some point, you would turn off the water flow...). It is a another "system" you have to install and maintain (both checking the charger+dump load, as well as keeping the turbine screens clear, managing water level, etc.). Is it worth it to you (energy usage is a highly personal set of choices--Some folks like "tinkering" with their power systems, others want an install and forget type installation).

    And a note, any off grid system needs to be looked at daily (or at least weekly), and monthly maintenance (which does eventually bring up battery type--Flooded Cell, AGM, LiFePO4, or other)... The larger the system, the more up front capital costs. Batteries last 3-5-8 years (forklift can be >15 years), electronics, plan on ~10+ years between replacement, sometimes repairs at 5+ years.

    Regarding geothermal--I would suggest looking at very efficient mini-split heat pumps instead. Geothermal can use some fairly large pumps for water circulation--Which eats into overall efficiency a lot. Using mini-splits also saves on air duct losses.

    Sizing your loads is very important--Different loads have different "issues". A laptop may use 30-60 Watts, but be used 10+ hours per day--Taking a 0.5 kWH ore more. However, a microwave using 1,500 Watts 20 minutes per day, only uses 500 WH (0.5 kWH) per day--same as a laptop. One pushes up the storage capacity because of total energy usage per day (WH), while the other pushes up battery bank size because of high surge/operational current (microwave, well pump, even a washing machine induction motor or HVAC/refrigerator compressor).

    And appliance selection is critical for system design... Especially for smaller systems. For example, a typical submersible pump may require a 4 kWatt AC inverter and a 400 AH @ 48 volt battery bank (minimum) to start the pump. However, if you get an "off grid friendly" well pump (more expensive at $1,000 to $2,000+), it may run on 900 Watt inverter (and 1/4 size battery bank) because they are soft start (VFD, variable frequency drive inside pump). Some models (more expensive) can run directly from solar panels (pump to cistern/pond during day, use a small house pressurization pump at night/bad weather).

    Similar for the newer "inverter" based Mini-Split AC systems--They have virtually no surge current and can be quite efficient compared to central air--And if you get a heat pump, can supply heating (from your solar system) pretty cost effectively too.

    Obviously how the home is/was built matters too (lots of insulation, shading during summer, winter sun through windows for heating during day, thermal mass possibly--Some folks try to find NON-E glass windows to get better winter heating). There are lots of ways to make things better for off grid.

    In general, a 3.3 kWH per day system is towards the small size of off grid power. May cost you $10-$20,000 for parts and installation... A 10-15 kWH per day system may cost you 3x as much. AC inverters and, today even solar panels are not the expensive part of the system--The major costs (installation and replacement costs) is the battery bank. You can limit the size of the battery bank to a degree by using it during the day time--However, solar panels do not supply surge current--And what happens if you have a cloud blow over (panel output drops by 50%) and such... I suggest designing the system to support 2 days of "no sun" (stormy weather) and 50% maximum discharge (longer battery life). If you have a spouse/kids/guests (or simply just need to get work done)--Waiting until sunny weather (or firing up the genset) my not be a desirable operational mode.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 29,637 admin
    edited October 2016 #5
    In your case--If the Volt is 1/2 of your load and is optional (i.e., no charging for it today)--Perhaps you can design for a much smaller system (5-8 kWH per day) and size it to manage the Volt... Note that to fully charge a Volt may take 12-16 hours at 120 VAC or 4 hours at 240 VAC (quick web search--need to do your own research for exact numbers). You can (roughly) expect most of your solar harvest from 9am to 3pm--Not enough time to charge at 120 VAC--And if you go with 240 VAC, you are looking at 3-4x more energy (larger array, larger inverter, larger battery bank?).<br><br>You can extend "hours of sunlight" with a tracker or "virtual tracking" (a larger array with 1/2 the panel facing south east and the other 1/2 facing south west). Obviously solar varies with seasons and weather. If you are willing to change tilt a couple times a year:

    Columbia
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 41° angle from vertical:
    (Optimal winter settings)
    Jan Feb Mar Apr May Jun
    3.87
     
    4.09
     
    4.76
     
    5.05
     
    4.77
     
    4.53
     
    Jul Aug Sep Oct Nov Dec
    4.53
     
    4.49
     
    4.58
     
    4.83
     
    Measured in kWh/m2/day onto a solar panel set at a 71° angle from vertical:
    (Optimal summer settings)
    Jan Feb Mar Apr May Jun
    3.27
     
    3.76
     
    4.77
     
    5.62
     
    5.79
     
    5.70
     
    Jul Aug Sep Oct Nov Dec
    5.60
     
    5.19
     
    4.79
     
    4.50
     
    3.64
     
    3.22
     
    First several years--You may be willing to manage the daily details of operating your system--A few years down the road, you may wish it to be more set and forget...

    This is your thread--Let us know where you would like to begin. I suggest not too many different questions at once--It can make for a confusing thread (possibly start a separate thread for specific question--such as off grid EV charging).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • WaterWheelWaterWheel Registered Users Posts: 328 ✭✭✭
    With hydro the alternator/impeller combination are usually designed to work optimally at a set flow and pressure so while you may have an additional jet that you can open in times of high flow you may not get full use of the additional flow.    So... yes, you may get a bit of additional power during rainy weather but I wouldn't use it as a reason to go with a marginal hydro source. 

    Since you're already willing to spend a lot of money for a good solar setup assuming your water flow is constant (Columbia has some very dry summers) I'd go for it even though it may be a little less cash efficient.      Even 1 kwh /day is a nice bit when you get 3 days worth of rain during the winter.

    Having lived in Lexington (close to Columbia) I know how hot the summers get.      Many people on this site are using high efficiency mini splits to cool their homes with solar.       I do here in a slightly cooler GA location and am currently discovering (my 1st fall with the mini split) that when it drops to 42 outside the mini split is keeping the home comfortable without overly stressing the batteries at night.        When it gets colder, maybe around 35 at night I'll light up the wood stoves but until then I'm enjoying keeping the house warm without the need for the wood stove.

    Conext XW6848 with PDP, SCP, 80/600 controller, 60/150 controller and Conext battery monitor

    21 SW280 panels on Schletter ground mount

    48v Rolls 6CS 27P

  • BB.BB. Super Moderators, Administrators Posts: 29,637 admin
    And as a counter to WaterWheel on the hydro...

    3kWH is 1 gallon of gasoline with a Honda eu2000i genset ($3 per gallon + $1,000 for genset) with ~4-9 hours of run-time.

    If you are already in need of a genset--The fuel offset by the hydro is not that much (cost/genset maintenance wise).

    In reality, if you are running a 10-15 kWH per day system--You are probably looking at a larger genset.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • solar_davesolar_dave Solar Expert Posts: 2,344 ✭✭✭✭
    Just as a BTW we have 2 Chevy Volts, in the last 2 years our monthly low consumption was 165 kWh and our high was 343 kWh with an average consumption per month ~250 kWh per month. One Volt gets driven a lot (about 10K miles annually) but the other is still a really low milage car (13K miles) at 5+ years old.  

    The 120 vs 240 chargers are about even on efficiency, our 240V charger draws 3600 watts while charging.  One is a Voltec and the other is a Clipper Creek, wired into a 60 amp sub-panel in the garage for future proofing.  I believe a full charge takes 13.5 kWh to get you about 40-45 miles of range.

    These are the cheapest cars to operate I ever own, the 2011 has only used 27 gallons of fuel since new and the 2012 has used about 270 gallons of fuel since new (this is the one we long distance in).  Oil Changes are every 2 years, just rotate the tires and watch the alignment to make sure the tires last, because of the regen-braking and the nitrided rotors I suspect the brakes will last forever. :wink:  Of course everyone watches the tire pressure cause keeping it near max makes for longer driving distances.  Right now I am starting to give a bit of worry to the 12V accessory batteries as they are now both over 5 years old. Car freaks out when the 12V battery dies.

    You can go over to this link: 
    http://www.coultersmithing.com/forums/viewtopic.php?f=48&t=759
    Doug has had a Volt for several years and only charges it off grid.  He uses charging the car as his major opportunity load.  He built what he calls a "Bang Bang" controller that runs off his battery charge controller to activate a 240 ESEV (charger). I see it has been a while since he updated it and his site is approval sign up to post.
  • InsolatedInsolated Registered Users Posts: 11 ✭✭
    I may need a little longer to digest everything -- lots of good information and thoughts.

    Just as a BTW we have 2 Chevy Volts...

    You can go over to this link: 
    Dave, you led me to the solar-electric forum from gm-volt.com. Thank you for that. I've learned a lot in both places. I remember reading Doug's posts way back when. Glad to see he's still doing well. What's sad is my biggest worry going off-grid is I'll have to manage my gas anxiety.


    "10% of your power from hydro ... is almost a don't care--It is round off error." That gets to the heart of the matter, and is probably what I needed to hear. "you may not get full use of the additional flow." reinforces that. "I'd go for it even though it may be a little less cash efficient. Even 1 kwh /day is a nice bit when you get 3 days worth of rain during the winter." That was my original thought, and I posted to see how off-base I was. Perhaps I will view hydro in my situation as a last priority, but not rule it out entirely.

    I definitely don't want to cause confusion. I'll leave battery types and mini-split heat pumps for other threads to create later. I've been considering the former and need to read up on the latter. Once I have more details on building the house, I'll create a separate post to discuss the best approach to essentials (well pump, etc.). I'll let this thread retain the topic of hydro for simplicity.

    Question:
    "However, solar panels do not supply surge current--And what happens if you have a cloud blow over (panel output drops by 50%) and such". My understanding had been the battery is intended to buffer such situations, if sufficiently sized. Can you not balance overpaneling with expected surge needs?
  • mike95490mike95490 Solar Expert Posts: 8,429 ✭✭✭✭✭
    Any chance your hydro gear can freeze in the winter?   Fun stuff.    I tried planning hydro for 2 years before I gave up on it.  It's nice steady power, but gear for the small spring does not scale up to river fed scale, the little system is still a little system, hard to grow it,
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • solar_davesolar_dave Solar Expert Posts: 2,344 ✭✭✭✭
    Insolated said:
    I may need a little longer to digest everything -- lots of good information and thoughts.

    <snip>

    Question:
    "However, solar panels do not supply surge current--And what happens if you have a cloud blow over (panel output drops by 50%) and such". My understanding had been the battery is intended to buffer such situations, if sufficiently sized. Can you not balance overpaneling with expected surge needs?
    The right way to size your system is of course start with the loads.  No over paneling is really expensive and would not work in all situations, really your battery bank should be capable of 2-3 days discharge with little charging, this would be due to long times of no direct sun.  Size your battery first then apply enough panel to the battery to reach a 10% rate of charge to keep it healthy.
  • WaterWheelWaterWheel Registered Users Posts: 328 ✭✭✭
    BB. said:
    And as a counter to WaterWheel on the hydro...
    3kWH is 1 gallon of gasoline with a Honda eu2000i genset ($3 per gallon + $1,000 for genset) with ~4-9 hours of run-time.
    If you are already in need of a genset--The fuel offset by the hydro is not that much (cost/genset maintenance wise).
    In reality, if you are running a 10-15 kWH per day system--You are probably looking at a larger genset.

    -Bill
    I've just always had a soft spot for hydro.      I build water wheels for a living and used to hook them to PMAs for some customers.     Some of my customers still do hook them to PMAs but if a person is primarily interested in making power I often refer them to turbines.... just wish I had a good hydro site.

    Conext XW6848 with PDP, SCP, 80/600 controller, 60/150 controller and Conext battery monitor

    21 SW280 panels on Schletter ground mount

    48v Rolls 6CS 27P

  • BB.BB. Super Moderators, Administrators Posts: 29,637 admin
    edited October 2016 #13
    Of course, I am not trying to say never build hydro--But, at least look at the economics of the installation and your personal commitment to installation and keeping it running.

    For lead acid batteries, there is a "sweet spot" of 2 days of storage and 50% maximum discharge (basically your battery bank is 4x your daily load). It works better for charging, and average surge load support, etc.

    If your run a 2x larger battery bank (1 day storage and 50% max discharge)--You may not have enough surge current support with flooded cell batteries (for example) to start a induction motor based well pump.

    Then you look other battery types--For example, AGM have much better surge current support--So you "pick" AGM and use a 1 day bank (1/2 size bank), but AGM costs 2x more (roughly) than flooded cell... So, your battery costs are about the same (and, on average, AGM have shorter life than flooded cell)...

    Why I suggest doing several (multiple) paper designs and see which will give you your best costs for supporting your loads.

    At this point, I believe that $6,000 for utility to your home will be less expensive (up front costs) than any off grid power system with the output power you are asking for. Add replacement batteries every 8 years or so, new electronics every 10+ years--Then $0.20 per kWH from the utility does not look so bad.

    You can always add a genset for backup power (few days, couple of weeks). Add Grid Tied power (to reduce costs, not backup power). And eventually a Hybrid of Off Grid solar backup power system.

    There is always the draw of being off the grid--But the econmics sometimes (most of the time) does not play fair.

    You might also think longer term... GT Solar is losing its subsidies (a few states have pretty much made GT solar impractical).. Also, what would be the price/value of the property if it had utility power.

    In general, off grid solar has very little value to most people purchasing a property. However, the costs you spend for utility power probably has more/better long term "investment value" (so far, the costs bringing in utility power is continuing to rise--So if you decide/or a new owner decides) to bring in utility power, later may cost substantially more (of course, it could be less if more folks move into the area and want utility power).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • pyintheyepyintheye Registered Users Posts: 35 ✭✭
    edited October 2016 #14
    Insolated said:
    I'm buying land that includes a spring-fed pond, with water constantly flowing out of the overflow pipe. For context, I'm looking into going off-grid using primarily solar -- I know that's a big discussion in itself, but I'd like to leave that to a later post, if you would, please. I want to discuss micro-hydro first so that, if it's not worth it, I can put it out of my mind and have less to focus on. (The summary on why off-grid: Tax credits of 30% federal and 25% state make batteries more attractive compared to a $6,000 grid connection cost.)

    The basic question: At what low wattage is installing micro-hydro not worth it? I don't know my loads yet, so I'm looking for guidelines and opinions; though I expect consumption of at least 10 kWh/day. I look at the hydro as offsetting lack of solar when it's raining or perhaps even just cloudy.

    Before I get into details, thank you to everyone in this community for all the information you provide on a daily basis. I've read this forum for around a year now and have learned a lot.

    * Pond size: 1 acre
    * Head (overflow pipe outlet): 11 - 21 m lower than pond surface (imprecision due to using GPS)
    Flow (sunny day, i.e. worst-case scenario): 0.625 L/s (determined using a bucket and timer, measured 3 times)

    Using PowerSpout.com's calculator (50 m pipe length, 100 mm pipe diameter), that's only 0.576 - 1.200 kWh/day, before losses. At, say, $1,875 ($2,500 before 25% state credit) to add the micro-hydro to the off-grid solar, amortized over 10 years, the addition costs $0.89/kWh - $0.43/kWh (again, before losses).

    How does rain improve that? I don't know. Annual rainfall is supposedly 44.59 inches in Columbia, SC. But how do I use that to estimate additional wattage from rain? That's apparently 4.5 million liters/year on a 1-acre pond, but isn't it too simplistic to just turn that into an additional 0.145 L/s?

    Thank you for your time.
    http://www.off-gridengineering.ca/OGEI/NH600.html
    I have been running this unit for 3+ years, fed from an enclosed spring. I have a new double pipe installation to take advantage of the increased water flow in the springtime. A 3/4" poly is my "always flowing" line and it is producing 21 watts @ 74lbs PSI at this time. During the springtime I will add a 1 1/4" flow that will run @ 68lbs PSI, so I shall see what that will give me for power.
    Previous to this latest tweak, I was running a 1" poly line @ 68lbs PSI and producing up to a 100 watts during the springtime, which would gradually decrease, into the summer. When the chance of freezing has past I would switch my system from a constant flow state to a static pressure state to increase the PSI to 76lbs running pressure. This would give me from 50 watts down to 21 watts, during summer into the fall season.
    MY little turbine is configured with 2 wiring setups that are changed with a toggle switch to maximize power output to match a Low flow/High flow scenario from my spring. Rob @ Off-Grid went out of his way to create a product that would give me constant power with as little as 3L/min flow = 6 watts.
    A constant trickle charge was what I was going for and that is what I have.
    Forgot to add, this is a 48 volt unit.

    Midnite Panel Box for MS4448PAE, FM60- 720w, FM80- 2340w, 8 Trojan L16H AC- 48V, NH600 Turbine, DHW 2000w opp/div load.
  • InsolatedInsolated Registered Users Posts: 11 ✭✭
    pyintheye said:
    Thank you for the product suggestion; I had not come across that one, and it sounds more targeted at my scenario than what I'd found. I'll have to contact them.
    mike95490 said:
    Any chance your hydro gear can freeze in the winter?
    I believe the flow is enough to prevent it, but good point; I'll have to double-check.
    BB. said:
    Of course, I am not trying to say never build hydro--But, at least look at the economics of the installation and your personal commitment to installation and keeping it running.
    ...
    Why I suggest doing several (multiple) paper designs and see which will give you your best costs for supporting your loads.
    ...
    There is always the draw of being off the grid--But the econmics sometimes (most of the time) does not play fair.

    You might also think longer term... GT Solar is losing its subsidies (a few states have pretty much made GT solar impractical).. Also, what would be the price/value of the property if it had utility power.
    ...
    Yes, the draw of being off-grid is strong. I've seen what's been happening with utilities and grid-tie solar, and it makes me nervous. I definitely want solar, even if it's not off-grid. You do make a good point about grid connection property value-wise; I don't expect to sell any time soon, but it's always a possibility. I thought I'd start with the off-grid approach and see where I ended up after discussion. I'll try to create a separate thread about loads soon.
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